1. Technical Field
This invention relates to portable pneumatic vacuum apparati and methods and, more particularly, to a portable pneumatic vacuum source including a source of pressurized fluid, a pressurized gas-driven ejector vacuum pump in fluid connection with the pressurized fluid source and a nozzle in vacuum connection with the vacuum pump such that fluid movement through the vacuum pump generates a vacuum in the nozzle, with a particular advantage being that the pressurized gas-driven vacuum pump is extremely quiet to allow for active listening for leaks in a vacuum system.
2. Description of the Prior Art
Vacuum sources are commonly used in connection with automobiles for testing a variety of automotive systems such as vacuum motors, control valves and pistons.
Various hand-operated vacuum sources have been proposed for providing a vacuum for testing of automobile vacuum systems, such as the Mityvac, produced by Neward Enterprises, Inc. of Cucamonga, Calif. Alternatively, various mechanical-type vacuum pumps have been used to generate a vacuum. These mechanical-type pumps are commonly driven by electric motors, internal combustion engines or various hydraulic systems and include such pump types as the piston pump, membrane pump, vane pump and Roots pump. The main disadvantage encountered in using such a mechanical pump, however, is that each of these pumps produces a relatively high level of noise which interferes with the ability of the operator to actively listen for leaks in a vacuum system. There is therefore a need for a substantially quiet vacuum-generating system for use in detecting leaks in vacuum systems of an automobile.
A similar problem encountered in the prior art is that most vacuum systems presently used in laboratory situations or in cleaning situations are quite noisy, due to the mechanical vacuum pump used in the system. While such systems are acceptable in some instances, a noisy system is unacceptable for use in sensitive experiments conducted in the laboratory or for use in cleaning in an office or work environment. For example, cleaning of computer keyboards and the like in large offices is preferably performed as quietly as possible, so as not to disturb other workers not affected by the cleaning process. It is also important that the vacuum system, in addition to being relatively silent, be generally portable to permit cleaning of various locations. Finally, it is important that the vacuum system be capable of producing a substantial level of airflow to thoroughly clean the surface selected for cleaning. At present, no example is found in the prior art which satisfies all of these requirements.
Another problem encountered in the prior art is that most vacuum-producing systems are not adjustable to provide different levels of vacuums. For example, most electric type vacuum pumps either are on or off, thus producing only a single level of vacuum when the device is activated. While such a system is acceptable for some uses, such as in a cleaning situation, these types of vacuum systems are clearly unacceptable for use in testing automobile systems or for use in laboratory situations. There is therefore a need for a vacuum source which will produce varying levels of vacuum quickly and accurately.
Various devices have been proposed in the prior art for detecting pressure leaks from various elements, including Himmelstein, 4,542,643, Soviet Union, 748-158, and Gandolfo, 3,377,844. However, none of these devices appear to be easily portable and all seem to utilize noisy mechanical-type vacuum pumps, which, as discussed previously, it is highly undesirable.
Therefore, an object of the present invention is to provide an improved portable pneumatic vacuum source.
Another object of the present invention is to provide a portable pneumatic vacuum source which includes a source of pressurized fluid, a pressurized gas-operated vacuum pump in fluid connection with the pressurized fluid source and a nozzle in vacuum connection with the vacuum pump.
Another object of the present invention is to provide a portable pneumatic vacuum source as described above which further includes a pressure regulator and filter combination interposed between the source of pressurized fluid and the vacuum pump and a relief valve intermediate the pressurized fluid source and vacuum pump for limiting pressure of the pressurized fluid.
Another object of the present invention is to provide a portable pneumatic vacuum source as described above which further includes a check valve intermediate the vacuum pump and nozzle for preventing loss of vacuum.
Another object of the present invention is to provide a portable pneumatic vacuum source which will not produce sound in excess of about 65 dBA.
Another object of the present invention is to provide a portable pneumatic vacuum source which may be used in connection with automobile systems, specifically for performing such processes as bleeding of brake lines, removal of air from hydraulic lines and testing of climate control systems to determine operational dampers within the system.
Another object of the present invention is to provide a method of testing vacuum systems in an automobile wherein the device described above is connected to a vacuum system of an automobile and vacuum is applied to the vacuum system, the quietness of the portable pneumatic vacuum source enabling the user to detect vacuum leaks by active listening.
Another object of the present invention is to provide a method for removing particulates from a surface which includes the steps of providing an apparatus such as described above and directing the nozzle of the apparatus to the area to be cleaned.
Another object of the present invention is to provide a portable pneumatic vacuum source which may be used to provide a vacuum in a laboratory situation.
Finally, an object of the present invention is to provide a portable pneumatic vacuum source and method of using same which is quiet, efficient and safe in use.